Genetic stability of hairy root cultures of Datura stramonium

The karyotypic status of three root lines, transformed with Agrobacterium rhizogenes, versus a non-transformed root line of Datura stramonium, as well as grown plants (control), was investigated. In the transformed cultures, the karyotype as well as the number of chromosomes (2n = 24) remained the same as in the control plants. In the normal root line there were clear differences at a morphological level despite showing the same chromosomic number (2n = 24) at a high frequency. The existence of aneuploids (2n = 2n ± x) and tetraploids (2n = 4x = 48) was also observed in the latter. The frequency of chromosomic alterations was very low in all the cultures. Cytogenetic analysis of the transformed root cultures of D. stramonium reported here shows a great chromosomic stability, which is not the case with normal root cultures. This revised version was published online in June 2006 with corrections to the Cover Date.